As a component of various types of display devices, such as a liquid crystal display device and an organic electroluminescent display device, a phase difference plate, that is, an optical member having a phase difference, is widely used.
As one of methods for obtaining a phase difference plate, there has been known a method in which a compound capable of exhibiting a liquid crystal phase is formed into a solid film while keeping the state of exhibiting the liquid crystal phase. Examples of such a method may include a method in which a film having optical anisotropy is formed by applying a composition containing various types of curable liquid crystal compounds, such as a polymerizable compound capable of exhibiting a liquid crystal phase, onto a surface of a suitable substrate to form a layer of the composition, giving orientation to the liquid crystal compounds in the layer, and then polymerizing the liquid crystal compounds while maintaining their orientation state. Employment of such a method enables to obtain a phase difference plate in which a phase difference is uniformly developed in a plate surface. Further, by properly selecting the liquid crystal compounds, it becomes possible to obtain a phase difference plate that causes a uniform phase difference in a visible light wavelength region (for example, Patent Literature 1).
As the method for giving orientation to such a compound capable of exhibiting a liquid crystal phase, a method wherein an orientation-regulation force is imparted to a surface of a substrate, a composition containing the compound capable of exhibiting a liquid crystal phase is applied onto the surface, and then the substrate is placed under conditions suitable for orientation is commonly performed. Examples of the method for imparting the orientation-regulation force to the surface of the substrate may include a method by rubbing (for example, Patent Literatures 2 and 3). Further, it is also known that orientation of the liquid crystal compound on the film may be achieved by use of a film that has been subjected to a stretching treatment as a substrate, whereby an efficient production is performed (for example, Patent Literature 4).